[C320-list] Marleon Seacocks

[Dave Hupe]

 I replaced the Marelon thruhull fitting and seacock for my head water intake last May.  I did this only because the thruhull was not seated well and had seeped previously. It was this assembly from Catalina Direct with a 3/4" barb (90 degree turn) for the hose https://www.catalinadirect.com/index.cfm/product/3517/seacock-34-flush-90-degree-hose-barb.cfm  I bedded the new thruhull fitting itself with 3M 5200 quick set.  After that set up, I bedded the seacock "nut"/base threads onto the thruhull with some 3M 4200 inside the boat.
Other seacock/thruhull assemblies on the boat are 3/4" straight hose barbs which are these at Catalina Direct https://www.catalinadirect.com/index.cfm/product/4532_1291/seacock-34-flush-straight-hose-barb.cfm
Either assembly (including the valve and thruhull fitting)  is about $102 total.  
Be careful if you do NOT order these from Catalina Direct or Catalina Yachts.  I found out (the hard way), that our flush type thruhull outer diameters are small (1.75" outer diameter) compared to those commonly available elsewhere (I found many online that looked right, but were 2 3/8" outer diameter which is too large for the flanged/sloped opening in the hull.
Removing the old assembly was easy.  Just unscrew (counterclockwise) the entire inside valve/seacock off the thruhull.  On the outside, use a utility knife and cut the old sealant line around the thruhull fitting (slope it inward since the hull opening is sloped inward toward the thruhull ), then push the thruhull out from the inside (you may need to tap on top of the thruhull fitting from inside with a hammer and wood block). Make sure to clean off the old sealant with acetone and sanding before installing the new assembly. 
Dave Hupe
1994 Cat320 (#32)
Holland, MI